Retrievable well pump



Dec. 22, 1953 A. G. GAGE RETRIEVABLE WELL PUMP Filed April 24, 195o fyd.

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Patented Dec. 22, "1953 UNITED STATES rTfENT orties RETRIEVABLE WELL PUMP Arthur G. Gage, Bell, Calif.

Application April 24, 1950, Serial No. 157,735 .17 Claims.` (Cl. 10S-46) This invention relates to improvements in well pumping systems of the type employing a pump submersible in the well iiuid and so associated with two pipe strings running from the pump to the ground surface, as to'be operable by fluid pressure communicated through one of the strings, to deliver the well production through the other string. y

More particularly, the invention is directed to such 'systems in which the pump isV adapted to be run down to seating or operating position within one of the pipe strings (preferably the inner of two strings one of which is contained in the other), and from which the pumpy is retrievable as by elevation on a wireline.

The invention is concernedprimarily with the removability of the pump for repair, inspection or replacement, and the pressure vrconditioning of the pumping system in a manner facilitating and assuring safe recovery of the pump.' Speciiically the invention has for its rmajor object the equalization, or near equalizationv of hydraulic` pressures applied to the pump, so as to permit its initial unseating and removal from the well on a wire line with only the pump load required to be carried by the line.

As illustrative, the invention will be described as embodied in apumping system employing inner and outer pipe strings, within the'former of f which the pump is run down to seating position.

Further as illustrative, the pump may be adapted for operation by iiuid pressure communicated through the inner string, the actuating fluid discharge and the production fluid being delivered up through the space between the two strings. Normally, upward displacement of the pump from seated position within a lower barrel extension of the inner string is resisted by the hydraulic pressure therein above the pump, which is greater than any effective pressure acting upwardly against the pump below its seat. Accordingly, in the absence of provision for balancing the hydraulic pressures applied k'downwardly and upwardly against the pump, removal of the pump on a wire line would require overcoming the differential of those pressures and imposition of unsafe loads on the wire line, at least until the pump is unseated.

I n accordance with the invention, provision is made for equalizing the pressures tending to seat and .unseat the pump, by the simple expedient of controlled communication to the underside of the pump by way of one of the hydraulic columns, and without requiring movement 2 of either' pipe string, of pressure suiicient to balance the pressure tending to seat the pump. The resulting'pressure balance then reduces the pump unseating load onthe retrieving wire line to the safe weight of the pump.

All the various objects of the invention, as well as the details of certain illustrative embodiments, will be fully understood from the following description of the systems illustrated by the coompanying drawing, in which:

Fig. 1 is a general view illustrating the pumping system, including the pipe string and pump assembly, and the flow lines at the ground surface; and

Fig. 2 is a fragmentary enlargement of the dual string and barrel assembly at the location of the pumps The` well pipe assembly comprises a diagrammatically illustrated outer pipe string lextend" ing from the ground surface down to the produc-l tion depth in the well and carrying seat ll engageable by the pump barrel as will later appear. Below the seat, the outer string has a production oil inlet l2, ,down flow through which normally is closed by a check valve i3 contained within a cage Ui seatable downwardly within the recess l5.

The inner string lt,.contained within and in spaced relation to the outer string ld, carries and may be regarded as including a pump barrel ll which normally seats downwardly against the seat il as illustrated in Fig. l. The barrel l? has alower yextension i la which receives the well uid enteringV chamber it through openings is. The -barrel extension lla has a suitable loose connection, such as a bolt 2t, with the check valve cage it, so that upon elevation of the in'- ner string, the cage and valve are lifted from their seats as shown in Fig. 2.

The inner string l5 carries a fluid pressure actuated pump 2i which may be of any of the usual types or" construction operable by fluid pressure communicated from the ground surface through the inner string and taken into the pump throughsits inlet 22, to receive well fluid through the lower end Zia of the pump, and discharge the combined actuating and production fluids through outlets 22 and the barrel port 23 into the space 24 between the pipe strings. The pump is Shown generally to comprise a fluidY driven motor section 5@ which operates by way of rod 5l the vertically reciprocating tubular or liquid passing plunger 52 carrying check valve l52, so that on its up stroke the plunger displaces well iiuid taken into the `pump body and plunger past check valve 152, together withthe motor operating uid exhausted at 53, through ports |22 and 23 into the column in space 24.

Thus normally, the inner string |6 contains an inner actuating uid column extending from above the pump to the ground surface, and space 24 between the strings contains an outer column of the production and exhausted actuating uids being pumped to the ground surface. The pump is adapted to be lowered within string I6 on a wire line 25 to operating position in which the pump is rested on the barrel seat 26. Fluid leakage between the pump and barrel may be prevented by suitable packing or seal rings 21 contained within recesses in the barrel and engaged against the pump surface. The pump is shown to carry a projection 26 releasably engageable by any suitable tool or overshot 29 carried by the wire line 25. The tool is shown typically to 'comprise a pair of crossed arms 55 pivoted at 56 Ifor engagement with the projection 2B, and releasable therefrom as by a go-devl 51 dropped on the wire line 25.

For purposes of normal operation, assume the pump to have been lowered to the seated position shown in Fig. l, with the wire line removed. Actuating fluid is delivered to the pump' through the inner hydraulic column from a suitable pressure source such as line 3U leading from a pump 3| and connecting with the pipe string below a normally closed gate 32. Production fluid is delivered through the outer column and line 33 to reservoir 34 or other disposal. During normal operation valves 35 and '36 in lines '30 and 33 are open, and valves 31 and '33 'in lines 39 and 40 are closed.

As will be understood, at 'such time as it may be desired to remove the pump from the well for purposes of inspection, repair or replacement, elevation of the pump from 'its seat 26 is resisted by the weight of the liquid column contained within the pipe string '|6 above the pump, or rthe differential between the pressure applied to the pump byv that column weight and the lesser pressure exerted upwardly against the lower end of the pump below its seat. Accordingly, in undertaking to remove the pump on the wire line, the latter must assume the column load or pressure differential at least until the pump is unseated, in the absence of an initial balancing of the pressures applied to the pump above and below its seat. In accordance with the invention, provision is made 'for effecting the balancing of such pressures by the transmission from the ground surface, and typically pump 3|, of abnormally high pressures by way of either of the fluid columns contained within the string |6 or space 24 between the Strings.

As best illustrated in Fig. 2, the pump barrel |1 may contain a passage 4| leading from a location above the pump or the upper seal 21, to the lower interior of the barrel below the pump seat 25. Passage 4| includes an enlarged bore 42 containing a check valve 43 normally seated by coil spring 44 having such resistance to opening of the Valve that the latter will remain seated at all normal operating pressures ofthe inner fluid column in string I6. At such time as it may be desirable to balance the pressures acting downwardly and upwardly against the pump, valves 36, 31 and 38 may be closed and pump 3| operated to build up within string I6 and passage 4| a pressure sufficient to unseat the check valve 43, whereupon corresponding pressure is communicated to barrel l'a, chamber I8 and the underside of the pump. Using a gate type fitting 32 capable of closing the string I6 above line 36, and capable also of pressure sealing about the line 25, the latter may be run down for attachment to the pump. With the pressure against the latter balanced, the only load imposed on the wire line for unseating an elevation of the pump, is only the weight of the pump itself.

As an alternative to the described means for balancing pressures on the pump through communication of pressure by way 'of the inner fluid column, provision also may be made for balancing the pressures by the communication of abnormally high iiuid pressure from the column in-space `24 to the underside of the pump. For this purpose may provide in the seat I a passage 46 normally closed by check valve 41 seated upwardly by coil spring 48. Normally, spring 46 maintains the check valve 41 seated to prevent fluid -'ow from the outer column into chamber I3. By closing valves 35 and 36 with valve 31 opened, pump 3| may operate to increase the outer fluid column pressure to a degree sunicient to unseat the valve 21 and communicate to chamber I8 and the pump housing lla a pressure sunlcient tc at least balance the fluid load on the top of vthe pump, and to facilitate its removal on the wire line in the manner previously explained. In view of the fact that any desired pressure may be thus communicated from the outer column 'to the underside of the pump, vit becomes possible to so exceed the hydrostatic load on the pump as to permit displacement or vpumping of the pump up through string to the exclusion of elevation by the wire line. A

At such time as may be desirable to remove the inner string I6 from the well, the string may be raised to unseat `the pump barrel from 'seat asy in the condition of Fig. 2, whereupon the inner fluid column drains through the pump into the outer column, and the latter in turn may restore to the normal well liquid level since 'elevation of the string opens the bottom check valve I3.

claimt l. The combination comprising a well pipe string, a pump seat carried by the lower portion of said string, a pump adapted to be lowered within said string into engagement with said seat and operable by fluid pressure communicated from the top of the well to pump 'fluid out of the well, upu'fard displacement of the pump from said seat normally being resisted by the pressure of a liquid column extending above the pump 'seat within said string to the top of the well and applied to an upwardly facing area of the pump, means 'within the 4well forming a passage adapted While the p'ump remains seated to communicate from a lower portion of said column to a downwardly facing area of the pump fluid ressure communicated from the top of the well through said column and sufficiently great to at least substantially equal the nuid pressure applied to said upwardly yiacinglarea of the pump, and valve means in the well continuously closing said passage to uid flow therethrough during normal operation of the pump. Y

2. The combination comprising a well pipe string, a pump seat carried by the lower portion of said string, a pump adapted to be lowered within said string into engagement with said seat 'and operable by. nuid pressure communicated from the top of the well to pump fluid out of the well., upward displacement of the pump from said seat normally being resisted by the pressure aeeaeer;

of a liquid column extending above the pump seat within said string to the top of the well and applied to an upwardly facing area of the pump, means within the well forming a passage adapted while the pump remains seated `to communicate from a lower portion of said column to a downwardly facing varea of the pump fluid pressure communicated from the top of the well through said column and sufficiently great to at least substantially equal the iluid pressure applied to said upwardly facing area of the pump, and a fluid pressure responsive valve in the well continuously closing said passage to fluid ilow therethrough during normal operation of the well.

3. The combination comprising a `well pipe string, a pump seat carried by the lower portion of said string, a pump adapted to be lowered within said string into engagement'withsaid seat and operable by fluid pressure communicated from the top of the well to pump fluid out of the well, upward. displacement of the pump from said seat normally being resisted by the pressure of a liquid column extending above the pump seat to the top of the well and applied to an upwardly facing area of the pump above said seat, means forming a passage adapted while the pump remains seated to apply to a downwardly facing area of the pump below said seat iluid pressure communicated from the top of the well and suiliciently reat to at least substantially equal the fluid pressure applied to said upwardly facing area of the pump, and Valve means in the well closing ofi said communication of fluid pressure to said downwardly facing area. of the pump through said passage during normal operation of the pump.

Ll. The combination comprising a well pipe string, a pump seat carried by the lower portion of said string, a pump adapted to oe lowered within said string into engagement with said seat and operable by iluid pressure communicated from the top of the well to pump fluid out of the well, upward displacement of the pump from said seat normally being resisted by the pressure of a liquid column extending above the pump seat to the top of the well and applied to an upn wardly facing area of the pump above said seat, means forming a passage through which fluid pressure communicated from the top of the well by way of said liquid column isapplicable to a downwardly facing area of the pump below said seat and to a degree sufcient to at least sub stantially equalize the pressures against saidy upwardly and downwardly facing area of the' pump, a spring-urged check valve normally closing fluid flow through said passage and operable to open in response to predetermined increase of the pump operating fluid pressure vto communicate that increased pressure to said downwardly facing area of the pump.

5. The combination comprising a well pipe string, a pump barrel carried by said string and containing a seat, a pump adapted to be lowered within said string onto said seat and operable by duid pressure communicated from the top of the well by way of a liquid column insaid string to pump fluid out of the well, upward displacement of the pump from said seat normally being resisted by the pressure of said column applied to an upwardly facing area of the pump, means forming in the wall of said barrel a passage through which increased pressure of said column communicated therethrough from the top of the well is applicable toa downwardly 6 facing areaV of the pump to a degree suillcient to at least substantially equalize the pressure against said areas, and a fluid pressure responsive Valve controlling the fluid flow through said passage.

6. The combination comprising a well pipe string, a pump barrel carried by said string and containing a seat, a pump adapted to be lowered within said string onto said seat and operable by iluid pressure communicated from the top of the well by way of a liquid column in said string to pump iluid out [of the well, upward displacement of the pump from said seat normally being resisted by the pressure of said column applied to an upwardly facing area of the pump, means forming in the wall of said barrel a passage through which increased pressure of said column is transmitted within the barrel from above said seat to below the seat and is applicable to a downwardly facing area of the pump to a degree sufficient to at least substantially equalize the pressure against said areas. a fluid pressure responsive valve controlling the fluid flow through said passage, and means carried by the pump for attachment to a wire line lowered in said pipe string to elevate the pump therein to the ground surface.

7. The combination comprising two spaced pipe strings lowered in a well one inside the other and containing inner and outer fluid columns, a seat within the lower portion of the outer string and a shoulder in the innerstring` normally engaged downwardly against said seat, said inner string including .a pump barrel containing a Dump seat, a pump adapted to be loweredlwithin the inner string onto said pump seat and operable by fluid pressure communicated from the top of the well by way of said inner fluid column to pump well fluid into said outer fluid column and to the ground surface, there being a fluid passage through which one of said columns is communicable with the barrel below said pump seat, and a valve in said passage closing such communication at normal column operating pressures and operable to establish such communication by the transmission from the top of the well of abnormally high pressure by way of said one of the columns, and thereby at least substantially equalize the pressures acting downwardly and upwardly :against the pump.

3. The combination comprising two spaced Apipe strings lowered in a well one inside the other and containing inner and outer fluid columns, a seat within the lower portion of the outer string and a shoulder in the inner string normally engaged downwardly against said seat, said inner string including a pump barrel containing a pump seat, a pump adapted to be lowered within the inner string onto said pump seat and operable by fluid pressure communicated from the top of the well by way of said inner fluid column to pump well fluid into said outer fluid columny and to the ground surface, there being a fluid passage through which one of said columns is communicable with the barrel below said pump seat, and a valve in said passage closing such communication at normal column operating pressures and operable to establish such communication by the transmission from the top of the well of abnormally high pressure by way of said one of the columns, and thereby at least substantially equalize the pressures acting downwardly and upwardly against the pump, and

means carried by the pump for attachment to da A aes-aser wire line lowered in the inner 'pipe `string to elevate the pump to the ground surface.

9. The combination comprising two spaced pipe strings lowered in a well one inside the other and containing inner and outer iluid colunins, a seat within the lower portion of the outer string and a. shoulder on the inner string normally engaged downwardly against said seat, said inner string including a pump barrel containing a pump seat, a pump adapted to be low-- ered within the inner string onto said pump seat and operable by fluid pressure communicated from the top of the well by way of said inner uid column to pump well uid into said outer fluid column and to the ground surface, there being a duid passage through which the inner fluid column is communicable with the barrel below pump seat, and a valve in said passage closing such communication at normal column operating pressures and operable to establish such communication by the transmission from the top of the well of abnormally high pressure by way of said inner column, and thereby at least substantially equalize the pressures acting downwardly and upwardly against the pump.

1G. The combination lcomprising two spaced pipe strings lowered in a well one inside the other and containing inner vand outer fluid columns, a seat within the lower portion of the outer string and a shoulder on the inner string normally engaged downwardly against said seat, said inner string including a pump barrel con#- taining .a pump seat, a pump adapted t-o be lowered within the inner string onto said pump seat and operable by fluid pressure communicated from the top of the well by way of said inner iluid column to pump well fluid into said `outer fluid column and to the ground surface, there being a iiuid passage through which the outer fluid column is communicable with the barrel below said pump seat, and a valve in said passage closing such communication at normal column operating pressures and operable to establish such communication by the transmission from the top of the well of abnormally high pressure ay way oi said outer column, and thereby at least substantially equalize the pressures acting downwardly and upwardly against the pump.

1l. The combination comprising two spaced pipe strings lowered in a well one inside 'the other and containing inner and outer fluid coluinns, a seat within the lower portion of the outer string and a shoulder Aon the inner string normally engaged downwardly against said seat, said inner including a pump barrel containing a pump seat, a pump adapted to be lowered within the inner string onto said pump seat and operable by iiuid pressure communicated from the top of the well by way of said inner fluid column to pump well fluid into said outer fluid column and to the ground surface, there being a fluid passage in the 'wall 'of Vsaid barrel extending between locations above and below the pump seat to communicate the inner column pressure to the under side of the pump, 'and a spring-urged check Valve in said passage closing such communication at normal inner column operating pressures and operable to establish such communication by the transmission from the ltop of the well of abnormally high pressure by way of the inner column and thereby at least substantially equalize the pressures acting downwardly and upwardly `against the pump.

12. The combination comprising two spaced pipe strings lowered in a well one inside the other and containing inner and outer fiuid columns, a seat within the lower portion of the outer string and a shoulder on the inner string normally engaged downwardly against said seat, said inner string including Aa pump barrel containing a pump seat, a pump adapted to be lowered within the inner string onto said pump seat and operable by iiuid pressure communicated from the top of the well by way of said inner ilui'd column to pump well iluid into said outer fluid column and to the ground surface, there being a iluid passage extending through the rst mentioned seat to communicate the outer `col*- umn pressure to the under side of the pump, and a spring-urged check valve in said .passage 'closing such communication as normal outer column operating pressures and voperable to establish such communication by the transmission from the top of the well of abnormally high pressures by way of the outer column, and thereby at least substantially equalize the pressures acting downwardly and upwardly against the pump.

13. The combination comprising two spaced pipe strings lowered kin `a well one inside `the other and containing inner and -outer fluid columns, an upwardly opening check valve closing fluid escape from a chamber in bottom of the outer pipe string directly above said chamber, a pump barrel included in the inner pipe string and seating downwardly against said seat, a pump seat within and carried by said barrel, a pump adapted to be lowered within the inner string onto said pump seat and `operable by fluid pressure communicated from the top of the 'well by way of said inner fluid column to pump well iiuid from said chamber into said outer Vfluid column and to the ground surface, a vertically reciprocable piston within the pump, a bottom check valve carried by the pump, and a connecttion between the inner pipe string and the first mentioned check valve whereby the latter may be opened by elevation of the inner string to drain iiuid from said chambers into the wells,

14. The combination comprising 'a iirst pipe string extending vertically within a well and containing a vertically eiitended liquid column, a second pipe string extending vertically within the well and disposed around said first string and containing another vertically extended liquid column at the outside of and extending substantially entirely about said first string, a pump seat carried by the lower portion or" said string, a pump adapted to be lowered within said first string into engagement with said seat and operable by iluid pressure communicated from the top `of the well through one of said columns to pump iiuid out of the well by Way of the other column, upward displacement of the pump from said seat normally being resisted by the pressure of one of said columns applied to an upwardly facing area of the pump, means within the well forming a passage adapted while the pump remains seated to communicate from a lower portion of the rst of said columns to a downwardly 'facing area of the pump huid pressure communicated from the top of the well by way oi said first column and suniciently great to at least substantially equal the fluid pressure .applied to said upwardly facing area of the pump, and valve means in the well continuously closing said passage to uid flow therethrough during vnormal operation of the pump.

15. A combination as recited in claim 14, and in which said valve means comprise a springurged check valve operable to open in response 1/ to predetermined increase in the pressure of said rst column to communicate that increased pressure to said downwardly facing area of the pump.

16. A combination as recited in claim l5, and in which said pump operating pressure is com- 5 municated through said first column.

17. A combination as recited. in claim 14, and including means carried by the pump for attaehment to a wire line lowered in said string to elevate the pump therein to the ground surface. 10

ARTHUR G. GAGE.

References Cited in the le 0f this patent Number UNITED STATES PATENTS n Name Date Swain Feb. e, 1941 Coberly F'eb. 4, 1941 Church Dee. 12, 1944 Coberly Mar. 18, 1952 

